xref: /linux/net/tls/tls_sw.c (revision 2c63221cd9e5c0dad0424029aeb1c40faada8330)
1 /*
2  * Copyright (c) 2016-2017, Mellanox Technologies. All rights reserved.
3  * Copyright (c) 2016-2017, Dave Watson <davejwatson@fb.com>. All rights reserved.
4  * Copyright (c) 2016-2017, Lance Chao <lancerchao@fb.com>. All rights reserved.
5  * Copyright (c) 2016, Fridolin Pokorny <fridolin.pokorny@gmail.com>. All rights reserved.
6  * Copyright (c) 2016, Nikos Mavrogiannopoulos <nmav@gnutls.org>. All rights reserved.
7  * Copyright (c) 2018, Covalent IO, Inc. http://covalent.io
8  *
9  * This software is available to you under a choice of one of two
10  * licenses.  You may choose to be licensed under the terms of the GNU
11  * General Public License (GPL) Version 2, available from the file
12  * COPYING in the main directory of this source tree, or the
13  * OpenIB.org BSD license below:
14  *
15  *     Redistribution and use in source and binary forms, with or
16  *     without modification, are permitted provided that the following
17  *     conditions are met:
18  *
19  *      - Redistributions of source code must retain the above
20  *        copyright notice, this list of conditions and the following
21  *        disclaimer.
22  *
23  *      - Redistributions in binary form must reproduce the above
24  *        copyright notice, this list of conditions and the following
25  *        disclaimer in the documentation and/or other materials
26  *        provided with the distribution.
27  *
28  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
29  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
30  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
31  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
32  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
33  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
34  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
35  * SOFTWARE.
36  */
37 
38 #include <linux/sched/signal.h>
39 #include <linux/module.h>
40 #include <crypto/aead.h>
41 
42 #include <net/strparser.h>
43 #include <net/tls.h>
44 
45 static int __skb_nsg(struct sk_buff *skb, int offset, int len,
46                      unsigned int recursion_level)
47 {
48         int start = skb_headlen(skb);
49         int i, chunk = start - offset;
50         struct sk_buff *frag_iter;
51         int elt = 0;
52 
53         if (unlikely(recursion_level >= 24))
54                 return -EMSGSIZE;
55 
56         if (chunk > 0) {
57                 if (chunk > len)
58                         chunk = len;
59                 elt++;
60                 len -= chunk;
61                 if (len == 0)
62                         return elt;
63                 offset += chunk;
64         }
65 
66         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
67                 int end;
68 
69                 WARN_ON(start > offset + len);
70 
71                 end = start + skb_frag_size(&skb_shinfo(skb)->frags[i]);
72                 chunk = end - offset;
73                 if (chunk > 0) {
74                         if (chunk > len)
75                                 chunk = len;
76                         elt++;
77                         len -= chunk;
78                         if (len == 0)
79                                 return elt;
80                         offset += chunk;
81                 }
82                 start = end;
83         }
84 
85         if (unlikely(skb_has_frag_list(skb))) {
86                 skb_walk_frags(skb, frag_iter) {
87                         int end, ret;
88 
89                         WARN_ON(start > offset + len);
90 
91                         end = start + frag_iter->len;
92                         chunk = end - offset;
93                         if (chunk > 0) {
94                                 if (chunk > len)
95                                         chunk = len;
96                                 ret = __skb_nsg(frag_iter, offset - start, chunk,
97                                                 recursion_level + 1);
98                                 if (unlikely(ret < 0))
99                                         return ret;
100                                 elt += ret;
101                                 len -= chunk;
102                                 if (len == 0)
103                                         return elt;
104                                 offset += chunk;
105                         }
106                         start = end;
107                 }
108         }
109         BUG_ON(len);
110         return elt;
111 }
112 
113 /* Return the number of scatterlist elements required to completely map the
114  * skb, or -EMSGSIZE if the recursion depth is exceeded.
115  */
116 static int skb_nsg(struct sk_buff *skb, int offset, int len)
117 {
118         return __skb_nsg(skb, offset, len, 0);
119 }
120 
121 static int padding_length(struct tls_sw_context_rx *ctx,
122 			  struct tls_prot_info *prot, struct sk_buff *skb)
123 {
124 	struct strp_msg *rxm = strp_msg(skb);
125 	int sub = 0;
126 
127 	/* Determine zero-padding length */
128 	if (prot->version == TLS_1_3_VERSION) {
129 		char content_type = 0;
130 		int err;
131 		int back = 17;
132 
133 		while (content_type == 0) {
134 			if (back > rxm->full_len - prot->prepend_size)
135 				return -EBADMSG;
136 			err = skb_copy_bits(skb,
137 					    rxm->offset + rxm->full_len - back,
138 					    &content_type, 1);
139 			if (err)
140 				return err;
141 			if (content_type)
142 				break;
143 			sub++;
144 			back++;
145 		}
146 		ctx->control = content_type;
147 	}
148 	return sub;
149 }
150 
151 static void tls_decrypt_done(struct crypto_async_request *req, int err)
152 {
153 	struct aead_request *aead_req = (struct aead_request *)req;
154 	struct scatterlist *sgout = aead_req->dst;
155 	struct scatterlist *sgin = aead_req->src;
156 	struct tls_sw_context_rx *ctx;
157 	struct tls_context *tls_ctx;
158 	struct tls_prot_info *prot;
159 	struct scatterlist *sg;
160 	struct sk_buff *skb;
161 	unsigned int pages;
162 	int pending;
163 
164 	skb = (struct sk_buff *)req->data;
165 	tls_ctx = tls_get_ctx(skb->sk);
166 	ctx = tls_sw_ctx_rx(tls_ctx);
167 	prot = &tls_ctx->prot_info;
168 
169 	/* Propagate if there was an err */
170 	if (err) {
171 		if (err == -EBADMSG)
172 			TLS_INC_STATS(sock_net(skb->sk),
173 				      LINUX_MIB_TLSDECRYPTERROR);
174 		ctx->async_wait.err = err;
175 		tls_err_abort(skb->sk, err);
176 	} else {
177 		struct strp_msg *rxm = strp_msg(skb);
178 		int pad;
179 
180 		pad = padding_length(ctx, prot, skb);
181 		if (pad < 0) {
182 			ctx->async_wait.err = pad;
183 			tls_err_abort(skb->sk, pad);
184 		} else {
185 			rxm->full_len -= pad;
186 			rxm->offset += prot->prepend_size;
187 			rxm->full_len -= prot->overhead_size;
188 		}
189 	}
190 
191 	/* After using skb->sk to propagate sk through crypto async callback
192 	 * we need to NULL it again.
193 	 */
194 	skb->sk = NULL;
195 
196 
197 	/* Free the destination pages if skb was not decrypted inplace */
198 	if (sgout != sgin) {
199 		/* Skip the first S/G entry as it points to AAD */
200 		for_each_sg(sg_next(sgout), sg, UINT_MAX, pages) {
201 			if (!sg)
202 				break;
203 			put_page(sg_page(sg));
204 		}
205 	}
206 
207 	kfree(aead_req);
208 
209 	pending = atomic_dec_return(&ctx->decrypt_pending);
210 
211 	if (!pending && READ_ONCE(ctx->async_notify))
212 		complete(&ctx->async_wait.completion);
213 }
214 
215 static int tls_do_decryption(struct sock *sk,
216 			     struct sk_buff *skb,
217 			     struct scatterlist *sgin,
218 			     struct scatterlist *sgout,
219 			     char *iv_recv,
220 			     size_t data_len,
221 			     struct aead_request *aead_req,
222 			     bool async)
223 {
224 	struct tls_context *tls_ctx = tls_get_ctx(sk);
225 	struct tls_prot_info *prot = &tls_ctx->prot_info;
226 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
227 	int ret;
228 
229 	aead_request_set_tfm(aead_req, ctx->aead_recv);
230 	aead_request_set_ad(aead_req, prot->aad_size);
231 	aead_request_set_crypt(aead_req, sgin, sgout,
232 			       data_len + prot->tag_size,
233 			       (u8 *)iv_recv);
234 
235 	if (async) {
236 		/* Using skb->sk to push sk through to crypto async callback
237 		 * handler. This allows propagating errors up to the socket
238 		 * if needed. It _must_ be cleared in the async handler
239 		 * before consume_skb is called. We _know_ skb->sk is NULL
240 		 * because it is a clone from strparser.
241 		 */
242 		skb->sk = sk;
243 		aead_request_set_callback(aead_req,
244 					  CRYPTO_TFM_REQ_MAY_BACKLOG,
245 					  tls_decrypt_done, skb);
246 		atomic_inc(&ctx->decrypt_pending);
247 	} else {
248 		aead_request_set_callback(aead_req,
249 					  CRYPTO_TFM_REQ_MAY_BACKLOG,
250 					  crypto_req_done, &ctx->async_wait);
251 	}
252 
253 	ret = crypto_aead_decrypt(aead_req);
254 	if (ret == -EINPROGRESS) {
255 		if (async)
256 			return ret;
257 
258 		ret = crypto_wait_req(ret, &ctx->async_wait);
259 	} else if (ret == -EBADMSG) {
260 		TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSDECRYPTERROR);
261 	}
262 
263 	if (async)
264 		atomic_dec(&ctx->decrypt_pending);
265 
266 	return ret;
267 }
268 
269 static void tls_trim_both_msgs(struct sock *sk, int target_size)
270 {
271 	struct tls_context *tls_ctx = tls_get_ctx(sk);
272 	struct tls_prot_info *prot = &tls_ctx->prot_info;
273 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
274 	struct tls_rec *rec = ctx->open_rec;
275 
276 	sk_msg_trim(sk, &rec->msg_plaintext, target_size);
277 	if (target_size > 0)
278 		target_size += prot->overhead_size;
279 	sk_msg_trim(sk, &rec->msg_encrypted, target_size);
280 }
281 
282 static int tls_alloc_encrypted_msg(struct sock *sk, int len)
283 {
284 	struct tls_context *tls_ctx = tls_get_ctx(sk);
285 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
286 	struct tls_rec *rec = ctx->open_rec;
287 	struct sk_msg *msg_en = &rec->msg_encrypted;
288 
289 	return sk_msg_alloc(sk, msg_en, len, 0);
290 }
291 
292 static int tls_clone_plaintext_msg(struct sock *sk, int required)
293 {
294 	struct tls_context *tls_ctx = tls_get_ctx(sk);
295 	struct tls_prot_info *prot = &tls_ctx->prot_info;
296 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
297 	struct tls_rec *rec = ctx->open_rec;
298 	struct sk_msg *msg_pl = &rec->msg_plaintext;
299 	struct sk_msg *msg_en = &rec->msg_encrypted;
300 	int skip, len;
301 
302 	/* We add page references worth len bytes from encrypted sg
303 	 * at the end of plaintext sg. It is guaranteed that msg_en
304 	 * has enough required room (ensured by caller).
305 	 */
306 	len = required - msg_pl->sg.size;
307 
308 	/* Skip initial bytes in msg_en's data to be able to use
309 	 * same offset of both plain and encrypted data.
310 	 */
311 	skip = prot->prepend_size + msg_pl->sg.size;
312 
313 	return sk_msg_clone(sk, msg_pl, msg_en, skip, len);
314 }
315 
316 static struct tls_rec *tls_get_rec(struct sock *sk)
317 {
318 	struct tls_context *tls_ctx = tls_get_ctx(sk);
319 	struct tls_prot_info *prot = &tls_ctx->prot_info;
320 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
321 	struct sk_msg *msg_pl, *msg_en;
322 	struct tls_rec *rec;
323 	int mem_size;
324 
325 	mem_size = sizeof(struct tls_rec) + crypto_aead_reqsize(ctx->aead_send);
326 
327 	rec = kzalloc(mem_size, sk->sk_allocation);
328 	if (!rec)
329 		return NULL;
330 
331 	msg_pl = &rec->msg_plaintext;
332 	msg_en = &rec->msg_encrypted;
333 
334 	sk_msg_init(msg_pl);
335 	sk_msg_init(msg_en);
336 
337 	sg_init_table(rec->sg_aead_in, 2);
338 	sg_set_buf(&rec->sg_aead_in[0], rec->aad_space, prot->aad_size);
339 	sg_unmark_end(&rec->sg_aead_in[1]);
340 
341 	sg_init_table(rec->sg_aead_out, 2);
342 	sg_set_buf(&rec->sg_aead_out[0], rec->aad_space, prot->aad_size);
343 	sg_unmark_end(&rec->sg_aead_out[1]);
344 
345 	return rec;
346 }
347 
348 static void tls_free_rec(struct sock *sk, struct tls_rec *rec)
349 {
350 	sk_msg_free(sk, &rec->msg_encrypted);
351 	sk_msg_free(sk, &rec->msg_plaintext);
352 	kfree(rec);
353 }
354 
355 static void tls_free_open_rec(struct sock *sk)
356 {
357 	struct tls_context *tls_ctx = tls_get_ctx(sk);
358 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
359 	struct tls_rec *rec = ctx->open_rec;
360 
361 	if (rec) {
362 		tls_free_rec(sk, rec);
363 		ctx->open_rec = NULL;
364 	}
365 }
366 
367 int tls_tx_records(struct sock *sk, int flags)
368 {
369 	struct tls_context *tls_ctx = tls_get_ctx(sk);
370 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
371 	struct tls_rec *rec, *tmp;
372 	struct sk_msg *msg_en;
373 	int tx_flags, rc = 0;
374 
375 	if (tls_is_partially_sent_record(tls_ctx)) {
376 		rec = list_first_entry(&ctx->tx_list,
377 				       struct tls_rec, list);
378 
379 		if (flags == -1)
380 			tx_flags = rec->tx_flags;
381 		else
382 			tx_flags = flags;
383 
384 		rc = tls_push_partial_record(sk, tls_ctx, tx_flags);
385 		if (rc)
386 			goto tx_err;
387 
388 		/* Full record has been transmitted.
389 		 * Remove the head of tx_list
390 		 */
391 		list_del(&rec->list);
392 		sk_msg_free(sk, &rec->msg_plaintext);
393 		kfree(rec);
394 	}
395 
396 	/* Tx all ready records */
397 	list_for_each_entry_safe(rec, tmp, &ctx->tx_list, list) {
398 		if (READ_ONCE(rec->tx_ready)) {
399 			if (flags == -1)
400 				tx_flags = rec->tx_flags;
401 			else
402 				tx_flags = flags;
403 
404 			msg_en = &rec->msg_encrypted;
405 			rc = tls_push_sg(sk, tls_ctx,
406 					 &msg_en->sg.data[msg_en->sg.curr],
407 					 0, tx_flags);
408 			if (rc)
409 				goto tx_err;
410 
411 			list_del(&rec->list);
412 			sk_msg_free(sk, &rec->msg_plaintext);
413 			kfree(rec);
414 		} else {
415 			break;
416 		}
417 	}
418 
419 tx_err:
420 	if (rc < 0 && rc != -EAGAIN)
421 		tls_err_abort(sk, EBADMSG);
422 
423 	return rc;
424 }
425 
426 static void tls_encrypt_done(struct crypto_async_request *req, int err)
427 {
428 	struct aead_request *aead_req = (struct aead_request *)req;
429 	struct sock *sk = req->data;
430 	struct tls_context *tls_ctx = tls_get_ctx(sk);
431 	struct tls_prot_info *prot = &tls_ctx->prot_info;
432 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
433 	struct scatterlist *sge;
434 	struct sk_msg *msg_en;
435 	struct tls_rec *rec;
436 	bool ready = false;
437 	int pending;
438 
439 	rec = container_of(aead_req, struct tls_rec, aead_req);
440 	msg_en = &rec->msg_encrypted;
441 
442 	sge = sk_msg_elem(msg_en, msg_en->sg.curr);
443 	sge->offset -= prot->prepend_size;
444 	sge->length += prot->prepend_size;
445 
446 	/* Check if error is previously set on socket */
447 	if (err || sk->sk_err) {
448 		rec = NULL;
449 
450 		/* If err is already set on socket, return the same code */
451 		if (sk->sk_err) {
452 			ctx->async_wait.err = sk->sk_err;
453 		} else {
454 			ctx->async_wait.err = err;
455 			tls_err_abort(sk, err);
456 		}
457 	}
458 
459 	if (rec) {
460 		struct tls_rec *first_rec;
461 
462 		/* Mark the record as ready for transmission */
463 		smp_store_mb(rec->tx_ready, true);
464 
465 		/* If received record is at head of tx_list, schedule tx */
466 		first_rec = list_first_entry(&ctx->tx_list,
467 					     struct tls_rec, list);
468 		if (rec == first_rec)
469 			ready = true;
470 	}
471 
472 	pending = atomic_dec_return(&ctx->encrypt_pending);
473 
474 	if (!pending && READ_ONCE(ctx->async_notify))
475 		complete(&ctx->async_wait.completion);
476 
477 	if (!ready)
478 		return;
479 
480 	/* Schedule the transmission */
481 	if (!test_and_set_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask))
482 		schedule_delayed_work(&ctx->tx_work.work, 1);
483 }
484 
485 static int tls_do_encryption(struct sock *sk,
486 			     struct tls_context *tls_ctx,
487 			     struct tls_sw_context_tx *ctx,
488 			     struct aead_request *aead_req,
489 			     size_t data_len, u32 start)
490 {
491 	struct tls_prot_info *prot = &tls_ctx->prot_info;
492 	struct tls_rec *rec = ctx->open_rec;
493 	struct sk_msg *msg_en = &rec->msg_encrypted;
494 	struct scatterlist *sge = sk_msg_elem(msg_en, start);
495 	int rc, iv_offset = 0;
496 
497 	/* For CCM based ciphers, first byte of IV is a constant */
498 	if (prot->cipher_type == TLS_CIPHER_AES_CCM_128) {
499 		rec->iv_data[0] = TLS_AES_CCM_IV_B0_BYTE;
500 		iv_offset = 1;
501 	}
502 
503 	memcpy(&rec->iv_data[iv_offset], tls_ctx->tx.iv,
504 	       prot->iv_size + prot->salt_size);
505 
506 	xor_iv_with_seq(prot->version, rec->iv_data, tls_ctx->tx.rec_seq);
507 
508 	sge->offset += prot->prepend_size;
509 	sge->length -= prot->prepend_size;
510 
511 	msg_en->sg.curr = start;
512 
513 	aead_request_set_tfm(aead_req, ctx->aead_send);
514 	aead_request_set_ad(aead_req, prot->aad_size);
515 	aead_request_set_crypt(aead_req, rec->sg_aead_in,
516 			       rec->sg_aead_out,
517 			       data_len, rec->iv_data);
518 
519 	aead_request_set_callback(aead_req, CRYPTO_TFM_REQ_MAY_BACKLOG,
520 				  tls_encrypt_done, sk);
521 
522 	/* Add the record in tx_list */
523 	list_add_tail((struct list_head *)&rec->list, &ctx->tx_list);
524 	atomic_inc(&ctx->encrypt_pending);
525 
526 	rc = crypto_aead_encrypt(aead_req);
527 	if (!rc || rc != -EINPROGRESS) {
528 		atomic_dec(&ctx->encrypt_pending);
529 		sge->offset -= prot->prepend_size;
530 		sge->length += prot->prepend_size;
531 	}
532 
533 	if (!rc) {
534 		WRITE_ONCE(rec->tx_ready, true);
535 	} else if (rc != -EINPROGRESS) {
536 		list_del(&rec->list);
537 		return rc;
538 	}
539 
540 	/* Unhook the record from context if encryption is not failure */
541 	ctx->open_rec = NULL;
542 	tls_advance_record_sn(sk, prot, &tls_ctx->tx);
543 	return rc;
544 }
545 
546 static int tls_split_open_record(struct sock *sk, struct tls_rec *from,
547 				 struct tls_rec **to, struct sk_msg *msg_opl,
548 				 struct sk_msg *msg_oen, u32 split_point,
549 				 u32 tx_overhead_size, u32 *orig_end)
550 {
551 	u32 i, j, bytes = 0, apply = msg_opl->apply_bytes;
552 	struct scatterlist *sge, *osge, *nsge;
553 	u32 orig_size = msg_opl->sg.size;
554 	struct scatterlist tmp = { };
555 	struct sk_msg *msg_npl;
556 	struct tls_rec *new;
557 	int ret;
558 
559 	new = tls_get_rec(sk);
560 	if (!new)
561 		return -ENOMEM;
562 	ret = sk_msg_alloc(sk, &new->msg_encrypted, msg_opl->sg.size +
563 			   tx_overhead_size, 0);
564 	if (ret < 0) {
565 		tls_free_rec(sk, new);
566 		return ret;
567 	}
568 
569 	*orig_end = msg_opl->sg.end;
570 	i = msg_opl->sg.start;
571 	sge = sk_msg_elem(msg_opl, i);
572 	while (apply && sge->length) {
573 		if (sge->length > apply) {
574 			u32 len = sge->length - apply;
575 
576 			get_page(sg_page(sge));
577 			sg_set_page(&tmp, sg_page(sge), len,
578 				    sge->offset + apply);
579 			sge->length = apply;
580 			bytes += apply;
581 			apply = 0;
582 		} else {
583 			apply -= sge->length;
584 			bytes += sge->length;
585 		}
586 
587 		sk_msg_iter_var_next(i);
588 		if (i == msg_opl->sg.end)
589 			break;
590 		sge = sk_msg_elem(msg_opl, i);
591 	}
592 
593 	msg_opl->sg.end = i;
594 	msg_opl->sg.curr = i;
595 	msg_opl->sg.copybreak = 0;
596 	msg_opl->apply_bytes = 0;
597 	msg_opl->sg.size = bytes;
598 
599 	msg_npl = &new->msg_plaintext;
600 	msg_npl->apply_bytes = apply;
601 	msg_npl->sg.size = orig_size - bytes;
602 
603 	j = msg_npl->sg.start;
604 	nsge = sk_msg_elem(msg_npl, j);
605 	if (tmp.length) {
606 		memcpy(nsge, &tmp, sizeof(*nsge));
607 		sk_msg_iter_var_next(j);
608 		nsge = sk_msg_elem(msg_npl, j);
609 	}
610 
611 	osge = sk_msg_elem(msg_opl, i);
612 	while (osge->length) {
613 		memcpy(nsge, osge, sizeof(*nsge));
614 		sg_unmark_end(nsge);
615 		sk_msg_iter_var_next(i);
616 		sk_msg_iter_var_next(j);
617 		if (i == *orig_end)
618 			break;
619 		osge = sk_msg_elem(msg_opl, i);
620 		nsge = sk_msg_elem(msg_npl, j);
621 	}
622 
623 	msg_npl->sg.end = j;
624 	msg_npl->sg.curr = j;
625 	msg_npl->sg.copybreak = 0;
626 
627 	*to = new;
628 	return 0;
629 }
630 
631 static void tls_merge_open_record(struct sock *sk, struct tls_rec *to,
632 				  struct tls_rec *from, u32 orig_end)
633 {
634 	struct sk_msg *msg_npl = &from->msg_plaintext;
635 	struct sk_msg *msg_opl = &to->msg_plaintext;
636 	struct scatterlist *osge, *nsge;
637 	u32 i, j;
638 
639 	i = msg_opl->sg.end;
640 	sk_msg_iter_var_prev(i);
641 	j = msg_npl->sg.start;
642 
643 	osge = sk_msg_elem(msg_opl, i);
644 	nsge = sk_msg_elem(msg_npl, j);
645 
646 	if (sg_page(osge) == sg_page(nsge) &&
647 	    osge->offset + osge->length == nsge->offset) {
648 		osge->length += nsge->length;
649 		put_page(sg_page(nsge));
650 	}
651 
652 	msg_opl->sg.end = orig_end;
653 	msg_opl->sg.curr = orig_end;
654 	msg_opl->sg.copybreak = 0;
655 	msg_opl->apply_bytes = msg_opl->sg.size + msg_npl->sg.size;
656 	msg_opl->sg.size += msg_npl->sg.size;
657 
658 	sk_msg_free(sk, &to->msg_encrypted);
659 	sk_msg_xfer_full(&to->msg_encrypted, &from->msg_encrypted);
660 
661 	kfree(from);
662 }
663 
664 static int tls_push_record(struct sock *sk, int flags,
665 			   unsigned char record_type)
666 {
667 	struct tls_context *tls_ctx = tls_get_ctx(sk);
668 	struct tls_prot_info *prot = &tls_ctx->prot_info;
669 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
670 	struct tls_rec *rec = ctx->open_rec, *tmp = NULL;
671 	u32 i, split_point, uninitialized_var(orig_end);
672 	struct sk_msg *msg_pl, *msg_en;
673 	struct aead_request *req;
674 	bool split;
675 	int rc;
676 
677 	if (!rec)
678 		return 0;
679 
680 	msg_pl = &rec->msg_plaintext;
681 	msg_en = &rec->msg_encrypted;
682 
683 	split_point = msg_pl->apply_bytes;
684 	split = split_point && split_point < msg_pl->sg.size;
685 	if (split) {
686 		rc = tls_split_open_record(sk, rec, &tmp, msg_pl, msg_en,
687 					   split_point, prot->overhead_size,
688 					   &orig_end);
689 		if (rc < 0)
690 			return rc;
691 		sk_msg_trim(sk, msg_en, msg_pl->sg.size +
692 			    prot->overhead_size);
693 	}
694 
695 	rec->tx_flags = flags;
696 	req = &rec->aead_req;
697 
698 	i = msg_pl->sg.end;
699 	sk_msg_iter_var_prev(i);
700 
701 	rec->content_type = record_type;
702 	if (prot->version == TLS_1_3_VERSION) {
703 		/* Add content type to end of message.  No padding added */
704 		sg_set_buf(&rec->sg_content_type, &rec->content_type, 1);
705 		sg_mark_end(&rec->sg_content_type);
706 		sg_chain(msg_pl->sg.data, msg_pl->sg.end + 1,
707 			 &rec->sg_content_type);
708 	} else {
709 		sg_mark_end(sk_msg_elem(msg_pl, i));
710 	}
711 
712 	i = msg_pl->sg.start;
713 	sg_chain(rec->sg_aead_in, 2, rec->inplace_crypto ?
714 		 &msg_en->sg.data[i] : &msg_pl->sg.data[i]);
715 
716 	i = msg_en->sg.end;
717 	sk_msg_iter_var_prev(i);
718 	sg_mark_end(sk_msg_elem(msg_en, i));
719 
720 	i = msg_en->sg.start;
721 	sg_chain(rec->sg_aead_out, 2, &msg_en->sg.data[i]);
722 
723 	tls_make_aad(rec->aad_space, msg_pl->sg.size + prot->tail_size,
724 		     tls_ctx->tx.rec_seq, prot->rec_seq_size,
725 		     record_type, prot->version);
726 
727 	tls_fill_prepend(tls_ctx,
728 			 page_address(sg_page(&msg_en->sg.data[i])) +
729 			 msg_en->sg.data[i].offset,
730 			 msg_pl->sg.size + prot->tail_size,
731 			 record_type, prot->version);
732 
733 	tls_ctx->pending_open_record_frags = false;
734 
735 	rc = tls_do_encryption(sk, tls_ctx, ctx, req,
736 			       msg_pl->sg.size + prot->tail_size, i);
737 	if (rc < 0) {
738 		if (rc != -EINPROGRESS) {
739 			tls_err_abort(sk, EBADMSG);
740 			if (split) {
741 				tls_ctx->pending_open_record_frags = true;
742 				tls_merge_open_record(sk, rec, tmp, orig_end);
743 			}
744 		}
745 		ctx->async_capable = 1;
746 		return rc;
747 	} else if (split) {
748 		msg_pl = &tmp->msg_plaintext;
749 		msg_en = &tmp->msg_encrypted;
750 		sk_msg_trim(sk, msg_en, msg_pl->sg.size + prot->overhead_size);
751 		tls_ctx->pending_open_record_frags = true;
752 		ctx->open_rec = tmp;
753 	}
754 
755 	return tls_tx_records(sk, flags);
756 }
757 
758 static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk,
759 			       bool full_record, u8 record_type,
760 			       size_t *copied, int flags)
761 {
762 	struct tls_context *tls_ctx = tls_get_ctx(sk);
763 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
764 	struct sk_msg msg_redir = { };
765 	struct sk_psock *psock;
766 	struct sock *sk_redir;
767 	struct tls_rec *rec;
768 	bool enospc, policy;
769 	int err = 0, send;
770 	u32 delta = 0;
771 
772 	policy = !(flags & MSG_SENDPAGE_NOPOLICY);
773 	psock = sk_psock_get(sk);
774 	if (!psock || !policy)
775 		return tls_push_record(sk, flags, record_type);
776 more_data:
777 	enospc = sk_msg_full(msg);
778 	if (psock->eval == __SK_NONE) {
779 		delta = msg->sg.size;
780 		psock->eval = sk_psock_msg_verdict(sk, psock, msg);
781 		if (delta < msg->sg.size)
782 			delta -= msg->sg.size;
783 		else
784 			delta = 0;
785 	}
786 	if (msg->cork_bytes && msg->cork_bytes > msg->sg.size &&
787 	    !enospc && !full_record) {
788 		err = -ENOSPC;
789 		goto out_err;
790 	}
791 	msg->cork_bytes = 0;
792 	send = msg->sg.size;
793 	if (msg->apply_bytes && msg->apply_bytes < send)
794 		send = msg->apply_bytes;
795 
796 	switch (psock->eval) {
797 	case __SK_PASS:
798 		err = tls_push_record(sk, flags, record_type);
799 		if (err < 0) {
800 			*copied -= sk_msg_free(sk, msg);
801 			tls_free_open_rec(sk);
802 			goto out_err;
803 		}
804 		break;
805 	case __SK_REDIRECT:
806 		sk_redir = psock->sk_redir;
807 		memcpy(&msg_redir, msg, sizeof(*msg));
808 		if (msg->apply_bytes < send)
809 			msg->apply_bytes = 0;
810 		else
811 			msg->apply_bytes -= send;
812 		sk_msg_return_zero(sk, msg, send);
813 		msg->sg.size -= send;
814 		release_sock(sk);
815 		err = tcp_bpf_sendmsg_redir(sk_redir, &msg_redir, send, flags);
816 		lock_sock(sk);
817 		if (err < 0) {
818 			*copied -= sk_msg_free_nocharge(sk, &msg_redir);
819 			msg->sg.size = 0;
820 		}
821 		if (msg->sg.size == 0)
822 			tls_free_open_rec(sk);
823 		break;
824 	case __SK_DROP:
825 	default:
826 		sk_msg_free_partial(sk, msg, send);
827 		if (msg->apply_bytes < send)
828 			msg->apply_bytes = 0;
829 		else
830 			msg->apply_bytes -= send;
831 		if (msg->sg.size == 0)
832 			tls_free_open_rec(sk);
833 		*copied -= (send + delta);
834 		err = -EACCES;
835 	}
836 
837 	if (likely(!err)) {
838 		bool reset_eval = !ctx->open_rec;
839 
840 		rec = ctx->open_rec;
841 		if (rec) {
842 			msg = &rec->msg_plaintext;
843 			if (!msg->apply_bytes)
844 				reset_eval = true;
845 		}
846 		if (reset_eval) {
847 			psock->eval = __SK_NONE;
848 			if (psock->sk_redir) {
849 				sock_put(psock->sk_redir);
850 				psock->sk_redir = NULL;
851 			}
852 		}
853 		if (rec)
854 			goto more_data;
855 	}
856  out_err:
857 	sk_psock_put(sk, psock);
858 	return err;
859 }
860 
861 static int tls_sw_push_pending_record(struct sock *sk, int flags)
862 {
863 	struct tls_context *tls_ctx = tls_get_ctx(sk);
864 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
865 	struct tls_rec *rec = ctx->open_rec;
866 	struct sk_msg *msg_pl;
867 	size_t copied;
868 
869 	if (!rec)
870 		return 0;
871 
872 	msg_pl = &rec->msg_plaintext;
873 	copied = msg_pl->sg.size;
874 	if (!copied)
875 		return 0;
876 
877 	return bpf_exec_tx_verdict(msg_pl, sk, true, TLS_RECORD_TYPE_DATA,
878 				   &copied, flags);
879 }
880 
881 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
882 {
883 	long timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
884 	struct tls_context *tls_ctx = tls_get_ctx(sk);
885 	struct tls_prot_info *prot = &tls_ctx->prot_info;
886 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
887 	bool async_capable = ctx->async_capable;
888 	unsigned char record_type = TLS_RECORD_TYPE_DATA;
889 	bool is_kvec = iov_iter_is_kvec(&msg->msg_iter);
890 	bool eor = !(msg->msg_flags & MSG_MORE);
891 	size_t try_to_copy, copied = 0;
892 	struct sk_msg *msg_pl, *msg_en;
893 	struct tls_rec *rec;
894 	int required_size;
895 	int num_async = 0;
896 	bool full_record;
897 	int record_room;
898 	int num_zc = 0;
899 	int orig_size;
900 	int ret = 0;
901 
902 	if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL))
903 		return -ENOTSUPP;
904 
905 	lock_sock(sk);
906 
907 	/* Wait till there is any pending write on socket */
908 	if (unlikely(sk->sk_write_pending)) {
909 		ret = wait_on_pending_writer(sk, &timeo);
910 		if (unlikely(ret))
911 			goto send_end;
912 	}
913 
914 	if (unlikely(msg->msg_controllen)) {
915 		ret = tls_proccess_cmsg(sk, msg, &record_type);
916 		if (ret) {
917 			if (ret == -EINPROGRESS)
918 				num_async++;
919 			else if (ret != -EAGAIN)
920 				goto send_end;
921 		}
922 	}
923 
924 	while (msg_data_left(msg)) {
925 		if (sk->sk_err) {
926 			ret = -sk->sk_err;
927 			goto send_end;
928 		}
929 
930 		if (ctx->open_rec)
931 			rec = ctx->open_rec;
932 		else
933 			rec = ctx->open_rec = tls_get_rec(sk);
934 		if (!rec) {
935 			ret = -ENOMEM;
936 			goto send_end;
937 		}
938 
939 		msg_pl = &rec->msg_plaintext;
940 		msg_en = &rec->msg_encrypted;
941 
942 		orig_size = msg_pl->sg.size;
943 		full_record = false;
944 		try_to_copy = msg_data_left(msg);
945 		record_room = TLS_MAX_PAYLOAD_SIZE - msg_pl->sg.size;
946 		if (try_to_copy >= record_room) {
947 			try_to_copy = record_room;
948 			full_record = true;
949 		}
950 
951 		required_size = msg_pl->sg.size + try_to_copy +
952 				prot->overhead_size;
953 
954 		if (!sk_stream_memory_free(sk))
955 			goto wait_for_sndbuf;
956 
957 alloc_encrypted:
958 		ret = tls_alloc_encrypted_msg(sk, required_size);
959 		if (ret) {
960 			if (ret != -ENOSPC)
961 				goto wait_for_memory;
962 
963 			/* Adjust try_to_copy according to the amount that was
964 			 * actually allocated. The difference is due
965 			 * to max sg elements limit
966 			 */
967 			try_to_copy -= required_size - msg_en->sg.size;
968 			full_record = true;
969 		}
970 
971 		if (!is_kvec && (full_record || eor) && !async_capable) {
972 			u32 first = msg_pl->sg.end;
973 
974 			ret = sk_msg_zerocopy_from_iter(sk, &msg->msg_iter,
975 							msg_pl, try_to_copy);
976 			if (ret)
977 				goto fallback_to_reg_send;
978 
979 			rec->inplace_crypto = 0;
980 
981 			num_zc++;
982 			copied += try_to_copy;
983 
984 			sk_msg_sg_copy_set(msg_pl, first);
985 			ret = bpf_exec_tx_verdict(msg_pl, sk, full_record,
986 						  record_type, &copied,
987 						  msg->msg_flags);
988 			if (ret) {
989 				if (ret == -EINPROGRESS)
990 					num_async++;
991 				else if (ret == -ENOMEM)
992 					goto wait_for_memory;
993 				else if (ret == -ENOSPC)
994 					goto rollback_iter;
995 				else if (ret != -EAGAIN)
996 					goto send_end;
997 			}
998 			continue;
999 rollback_iter:
1000 			copied -= try_to_copy;
1001 			sk_msg_sg_copy_clear(msg_pl, first);
1002 			iov_iter_revert(&msg->msg_iter,
1003 					msg_pl->sg.size - orig_size);
1004 fallback_to_reg_send:
1005 			sk_msg_trim(sk, msg_pl, orig_size);
1006 		}
1007 
1008 		required_size = msg_pl->sg.size + try_to_copy;
1009 
1010 		ret = tls_clone_plaintext_msg(sk, required_size);
1011 		if (ret) {
1012 			if (ret != -ENOSPC)
1013 				goto send_end;
1014 
1015 			/* Adjust try_to_copy according to the amount that was
1016 			 * actually allocated. The difference is due
1017 			 * to max sg elements limit
1018 			 */
1019 			try_to_copy -= required_size - msg_pl->sg.size;
1020 			full_record = true;
1021 			sk_msg_trim(sk, msg_en,
1022 				    msg_pl->sg.size + prot->overhead_size);
1023 		}
1024 
1025 		if (try_to_copy) {
1026 			ret = sk_msg_memcopy_from_iter(sk, &msg->msg_iter,
1027 						       msg_pl, try_to_copy);
1028 			if (ret < 0)
1029 				goto trim_sgl;
1030 		}
1031 
1032 		/* Open records defined only if successfully copied, otherwise
1033 		 * we would trim the sg but not reset the open record frags.
1034 		 */
1035 		tls_ctx->pending_open_record_frags = true;
1036 		copied += try_to_copy;
1037 		if (full_record || eor) {
1038 			ret = bpf_exec_tx_verdict(msg_pl, sk, full_record,
1039 						  record_type, &copied,
1040 						  msg->msg_flags);
1041 			if (ret) {
1042 				if (ret == -EINPROGRESS)
1043 					num_async++;
1044 				else if (ret == -ENOMEM)
1045 					goto wait_for_memory;
1046 				else if (ret != -EAGAIN) {
1047 					if (ret == -ENOSPC)
1048 						ret = 0;
1049 					goto send_end;
1050 				}
1051 			}
1052 		}
1053 
1054 		continue;
1055 
1056 wait_for_sndbuf:
1057 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1058 wait_for_memory:
1059 		ret = sk_stream_wait_memory(sk, &timeo);
1060 		if (ret) {
1061 trim_sgl:
1062 			tls_trim_both_msgs(sk, orig_size);
1063 			goto send_end;
1064 		}
1065 
1066 		if (msg_en->sg.size < required_size)
1067 			goto alloc_encrypted;
1068 	}
1069 
1070 	if (!num_async) {
1071 		goto send_end;
1072 	} else if (num_zc) {
1073 		/* Wait for pending encryptions to get completed */
1074 		smp_store_mb(ctx->async_notify, true);
1075 
1076 		if (atomic_read(&ctx->encrypt_pending))
1077 			crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
1078 		else
1079 			reinit_completion(&ctx->async_wait.completion);
1080 
1081 		WRITE_ONCE(ctx->async_notify, false);
1082 
1083 		if (ctx->async_wait.err) {
1084 			ret = ctx->async_wait.err;
1085 			copied = 0;
1086 		}
1087 	}
1088 
1089 	/* Transmit if any encryptions have completed */
1090 	if (test_and_clear_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask)) {
1091 		cancel_delayed_work(&ctx->tx_work.work);
1092 		tls_tx_records(sk, msg->msg_flags);
1093 	}
1094 
1095 send_end:
1096 	ret = sk_stream_error(sk, msg->msg_flags, ret);
1097 
1098 	release_sock(sk);
1099 	return copied ? copied : ret;
1100 }
1101 
1102 static int tls_sw_do_sendpage(struct sock *sk, struct page *page,
1103 			      int offset, size_t size, int flags)
1104 {
1105 	long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
1106 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1107 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
1108 	struct tls_prot_info *prot = &tls_ctx->prot_info;
1109 	unsigned char record_type = TLS_RECORD_TYPE_DATA;
1110 	struct sk_msg *msg_pl;
1111 	struct tls_rec *rec;
1112 	int num_async = 0;
1113 	size_t copied = 0;
1114 	bool full_record;
1115 	int record_room;
1116 	int ret = 0;
1117 	bool eor;
1118 
1119 	eor = !(flags & (MSG_MORE | MSG_SENDPAGE_NOTLAST));
1120 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1121 
1122 	/* Wait till there is any pending write on socket */
1123 	if (unlikely(sk->sk_write_pending)) {
1124 		ret = wait_on_pending_writer(sk, &timeo);
1125 		if (unlikely(ret))
1126 			goto sendpage_end;
1127 	}
1128 
1129 	/* Call the sk_stream functions to manage the sndbuf mem. */
1130 	while (size > 0) {
1131 		size_t copy, required_size;
1132 
1133 		if (sk->sk_err) {
1134 			ret = -sk->sk_err;
1135 			goto sendpage_end;
1136 		}
1137 
1138 		if (ctx->open_rec)
1139 			rec = ctx->open_rec;
1140 		else
1141 			rec = ctx->open_rec = tls_get_rec(sk);
1142 		if (!rec) {
1143 			ret = -ENOMEM;
1144 			goto sendpage_end;
1145 		}
1146 
1147 		msg_pl = &rec->msg_plaintext;
1148 
1149 		full_record = false;
1150 		record_room = TLS_MAX_PAYLOAD_SIZE - msg_pl->sg.size;
1151 		copy = size;
1152 		if (copy >= record_room) {
1153 			copy = record_room;
1154 			full_record = true;
1155 		}
1156 
1157 		required_size = msg_pl->sg.size + copy + prot->overhead_size;
1158 
1159 		if (!sk_stream_memory_free(sk))
1160 			goto wait_for_sndbuf;
1161 alloc_payload:
1162 		ret = tls_alloc_encrypted_msg(sk, required_size);
1163 		if (ret) {
1164 			if (ret != -ENOSPC)
1165 				goto wait_for_memory;
1166 
1167 			/* Adjust copy according to the amount that was
1168 			 * actually allocated. The difference is due
1169 			 * to max sg elements limit
1170 			 */
1171 			copy -= required_size - msg_pl->sg.size;
1172 			full_record = true;
1173 		}
1174 
1175 		sk_msg_page_add(msg_pl, page, copy, offset);
1176 		sk_mem_charge(sk, copy);
1177 
1178 		offset += copy;
1179 		size -= copy;
1180 		copied += copy;
1181 
1182 		tls_ctx->pending_open_record_frags = true;
1183 		if (full_record || eor || sk_msg_full(msg_pl)) {
1184 			rec->inplace_crypto = 0;
1185 			ret = bpf_exec_tx_verdict(msg_pl, sk, full_record,
1186 						  record_type, &copied, flags);
1187 			if (ret) {
1188 				if (ret == -EINPROGRESS)
1189 					num_async++;
1190 				else if (ret == -ENOMEM)
1191 					goto wait_for_memory;
1192 				else if (ret != -EAGAIN) {
1193 					if (ret == -ENOSPC)
1194 						ret = 0;
1195 					goto sendpage_end;
1196 				}
1197 			}
1198 		}
1199 		continue;
1200 wait_for_sndbuf:
1201 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1202 wait_for_memory:
1203 		ret = sk_stream_wait_memory(sk, &timeo);
1204 		if (ret) {
1205 			tls_trim_both_msgs(sk, msg_pl->sg.size);
1206 			goto sendpage_end;
1207 		}
1208 
1209 		goto alloc_payload;
1210 	}
1211 
1212 	if (num_async) {
1213 		/* Transmit if any encryptions have completed */
1214 		if (test_and_clear_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask)) {
1215 			cancel_delayed_work(&ctx->tx_work.work);
1216 			tls_tx_records(sk, flags);
1217 		}
1218 	}
1219 sendpage_end:
1220 	ret = sk_stream_error(sk, flags, ret);
1221 	return copied ? copied : ret;
1222 }
1223 
1224 int tls_sw_sendpage(struct sock *sk, struct page *page,
1225 		    int offset, size_t size, int flags)
1226 {
1227 	int ret;
1228 
1229 	if (flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL |
1230 		      MSG_SENDPAGE_NOTLAST | MSG_SENDPAGE_NOPOLICY))
1231 		return -ENOTSUPP;
1232 
1233 	lock_sock(sk);
1234 	ret = tls_sw_do_sendpage(sk, page, offset, size, flags);
1235 	release_sock(sk);
1236 	return ret;
1237 }
1238 
1239 static struct sk_buff *tls_wait_data(struct sock *sk, struct sk_psock *psock,
1240 				     int flags, long timeo, int *err)
1241 {
1242 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1243 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
1244 	struct sk_buff *skb;
1245 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
1246 
1247 	while (!(skb = ctx->recv_pkt) && sk_psock_queue_empty(psock)) {
1248 		if (sk->sk_err) {
1249 			*err = sock_error(sk);
1250 			return NULL;
1251 		}
1252 
1253 		if (sk->sk_shutdown & RCV_SHUTDOWN)
1254 			return NULL;
1255 
1256 		if (sock_flag(sk, SOCK_DONE))
1257 			return NULL;
1258 
1259 		if ((flags & MSG_DONTWAIT) || !timeo) {
1260 			*err = -EAGAIN;
1261 			return NULL;
1262 		}
1263 
1264 		add_wait_queue(sk_sleep(sk), &wait);
1265 		sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
1266 		sk_wait_event(sk, &timeo,
1267 			      ctx->recv_pkt != skb ||
1268 			      !sk_psock_queue_empty(psock),
1269 			      &wait);
1270 		sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
1271 		remove_wait_queue(sk_sleep(sk), &wait);
1272 
1273 		/* Handle signals */
1274 		if (signal_pending(current)) {
1275 			*err = sock_intr_errno(timeo);
1276 			return NULL;
1277 		}
1278 	}
1279 
1280 	return skb;
1281 }
1282 
1283 static int tls_setup_from_iter(struct sock *sk, struct iov_iter *from,
1284 			       int length, int *pages_used,
1285 			       unsigned int *size_used,
1286 			       struct scatterlist *to,
1287 			       int to_max_pages)
1288 {
1289 	int rc = 0, i = 0, num_elem = *pages_used, maxpages;
1290 	struct page *pages[MAX_SKB_FRAGS];
1291 	unsigned int size = *size_used;
1292 	ssize_t copied, use;
1293 	size_t offset;
1294 
1295 	while (length > 0) {
1296 		i = 0;
1297 		maxpages = to_max_pages - num_elem;
1298 		if (maxpages == 0) {
1299 			rc = -EFAULT;
1300 			goto out;
1301 		}
1302 		copied = iov_iter_get_pages(from, pages,
1303 					    length,
1304 					    maxpages, &offset);
1305 		if (copied <= 0) {
1306 			rc = -EFAULT;
1307 			goto out;
1308 		}
1309 
1310 		iov_iter_advance(from, copied);
1311 
1312 		length -= copied;
1313 		size += copied;
1314 		while (copied) {
1315 			use = min_t(int, copied, PAGE_SIZE - offset);
1316 
1317 			sg_set_page(&to[num_elem],
1318 				    pages[i], use, offset);
1319 			sg_unmark_end(&to[num_elem]);
1320 			/* We do not uncharge memory from this API */
1321 
1322 			offset = 0;
1323 			copied -= use;
1324 
1325 			i++;
1326 			num_elem++;
1327 		}
1328 	}
1329 	/* Mark the end in the last sg entry if newly added */
1330 	if (num_elem > *pages_used)
1331 		sg_mark_end(&to[num_elem - 1]);
1332 out:
1333 	if (rc)
1334 		iov_iter_revert(from, size - *size_used);
1335 	*size_used = size;
1336 	*pages_used = num_elem;
1337 
1338 	return rc;
1339 }
1340 
1341 /* This function decrypts the input skb into either out_iov or in out_sg
1342  * or in skb buffers itself. The input parameter 'zc' indicates if
1343  * zero-copy mode needs to be tried or not. With zero-copy mode, either
1344  * out_iov or out_sg must be non-NULL. In case both out_iov and out_sg are
1345  * NULL, then the decryption happens inside skb buffers itself, i.e.
1346  * zero-copy gets disabled and 'zc' is updated.
1347  */
1348 
1349 static int decrypt_internal(struct sock *sk, struct sk_buff *skb,
1350 			    struct iov_iter *out_iov,
1351 			    struct scatterlist *out_sg,
1352 			    int *chunk, bool *zc, bool async)
1353 {
1354 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1355 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
1356 	struct tls_prot_info *prot = &tls_ctx->prot_info;
1357 	struct strp_msg *rxm = strp_msg(skb);
1358 	int n_sgin, n_sgout, nsg, mem_size, aead_size, err, pages = 0;
1359 	struct aead_request *aead_req;
1360 	struct sk_buff *unused;
1361 	u8 *aad, *iv, *mem = NULL;
1362 	struct scatterlist *sgin = NULL;
1363 	struct scatterlist *sgout = NULL;
1364 	const int data_len = rxm->full_len - prot->overhead_size +
1365 			     prot->tail_size;
1366 	int iv_offset = 0;
1367 
1368 	if (*zc && (out_iov || out_sg)) {
1369 		if (out_iov)
1370 			n_sgout = iov_iter_npages(out_iov, INT_MAX) + 1;
1371 		else
1372 			n_sgout = sg_nents(out_sg);
1373 		n_sgin = skb_nsg(skb, rxm->offset + prot->prepend_size,
1374 				 rxm->full_len - prot->prepend_size);
1375 	} else {
1376 		n_sgout = 0;
1377 		*zc = false;
1378 		n_sgin = skb_cow_data(skb, 0, &unused);
1379 	}
1380 
1381 	if (n_sgin < 1)
1382 		return -EBADMSG;
1383 
1384 	/* Increment to accommodate AAD */
1385 	n_sgin = n_sgin + 1;
1386 
1387 	nsg = n_sgin + n_sgout;
1388 
1389 	aead_size = sizeof(*aead_req) + crypto_aead_reqsize(ctx->aead_recv);
1390 	mem_size = aead_size + (nsg * sizeof(struct scatterlist));
1391 	mem_size = mem_size + prot->aad_size;
1392 	mem_size = mem_size + crypto_aead_ivsize(ctx->aead_recv);
1393 
1394 	/* Allocate a single block of memory which contains
1395 	 * aead_req || sgin[] || sgout[] || aad || iv.
1396 	 * This order achieves correct alignment for aead_req, sgin, sgout.
1397 	 */
1398 	mem = kmalloc(mem_size, sk->sk_allocation);
1399 	if (!mem)
1400 		return -ENOMEM;
1401 
1402 	/* Segment the allocated memory */
1403 	aead_req = (struct aead_request *)mem;
1404 	sgin = (struct scatterlist *)(mem + aead_size);
1405 	sgout = sgin + n_sgin;
1406 	aad = (u8 *)(sgout + n_sgout);
1407 	iv = aad + prot->aad_size;
1408 
1409 	/* For CCM based ciphers, first byte of nonce+iv is always '2' */
1410 	if (prot->cipher_type == TLS_CIPHER_AES_CCM_128) {
1411 		iv[0] = 2;
1412 		iv_offset = 1;
1413 	}
1414 
1415 	/* Prepare IV */
1416 	err = skb_copy_bits(skb, rxm->offset + TLS_HEADER_SIZE,
1417 			    iv + iv_offset + prot->salt_size,
1418 			    prot->iv_size);
1419 	if (err < 0) {
1420 		kfree(mem);
1421 		return err;
1422 	}
1423 	if (prot->version == TLS_1_3_VERSION)
1424 		memcpy(iv + iv_offset, tls_ctx->rx.iv,
1425 		       crypto_aead_ivsize(ctx->aead_recv));
1426 	else
1427 		memcpy(iv + iv_offset, tls_ctx->rx.iv, prot->salt_size);
1428 
1429 	xor_iv_with_seq(prot->version, iv, tls_ctx->rx.rec_seq);
1430 
1431 	/* Prepare AAD */
1432 	tls_make_aad(aad, rxm->full_len - prot->overhead_size +
1433 		     prot->tail_size,
1434 		     tls_ctx->rx.rec_seq, prot->rec_seq_size,
1435 		     ctx->control, prot->version);
1436 
1437 	/* Prepare sgin */
1438 	sg_init_table(sgin, n_sgin);
1439 	sg_set_buf(&sgin[0], aad, prot->aad_size);
1440 	err = skb_to_sgvec(skb, &sgin[1],
1441 			   rxm->offset + prot->prepend_size,
1442 			   rxm->full_len - prot->prepend_size);
1443 	if (err < 0) {
1444 		kfree(mem);
1445 		return err;
1446 	}
1447 
1448 	if (n_sgout) {
1449 		if (out_iov) {
1450 			sg_init_table(sgout, n_sgout);
1451 			sg_set_buf(&sgout[0], aad, prot->aad_size);
1452 
1453 			*chunk = 0;
1454 			err = tls_setup_from_iter(sk, out_iov, data_len,
1455 						  &pages, chunk, &sgout[1],
1456 						  (n_sgout - 1));
1457 			if (err < 0)
1458 				goto fallback_to_reg_recv;
1459 		} else if (out_sg) {
1460 			memcpy(sgout, out_sg, n_sgout * sizeof(*sgout));
1461 		} else {
1462 			goto fallback_to_reg_recv;
1463 		}
1464 	} else {
1465 fallback_to_reg_recv:
1466 		sgout = sgin;
1467 		pages = 0;
1468 		*chunk = data_len;
1469 		*zc = false;
1470 	}
1471 
1472 	/* Prepare and submit AEAD request */
1473 	err = tls_do_decryption(sk, skb, sgin, sgout, iv,
1474 				data_len, aead_req, async);
1475 	if (err == -EINPROGRESS)
1476 		return err;
1477 
1478 	/* Release the pages in case iov was mapped to pages */
1479 	for (; pages > 0; pages--)
1480 		put_page(sg_page(&sgout[pages]));
1481 
1482 	kfree(mem);
1483 	return err;
1484 }
1485 
1486 static int decrypt_skb_update(struct sock *sk, struct sk_buff *skb,
1487 			      struct iov_iter *dest, int *chunk, bool *zc,
1488 			      bool async)
1489 {
1490 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1491 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
1492 	struct tls_prot_info *prot = &tls_ctx->prot_info;
1493 	struct strp_msg *rxm = strp_msg(skb);
1494 	int pad, err = 0;
1495 
1496 	if (!ctx->decrypted) {
1497 		if (tls_ctx->rx_conf == TLS_HW) {
1498 			err = tls_device_decrypted(sk, tls_ctx, skb, rxm);
1499 			if (err < 0)
1500 				return err;
1501 		}
1502 
1503 		/* Still not decrypted after tls_device */
1504 		if (!ctx->decrypted) {
1505 			err = decrypt_internal(sk, skb, dest, NULL, chunk, zc,
1506 					       async);
1507 			if (err < 0) {
1508 				if (err == -EINPROGRESS)
1509 					tls_advance_record_sn(sk, prot,
1510 							      &tls_ctx->rx);
1511 
1512 				return err;
1513 			}
1514 		} else {
1515 			*zc = false;
1516 		}
1517 
1518 		pad = padding_length(ctx, prot, skb);
1519 		if (pad < 0)
1520 			return pad;
1521 
1522 		rxm->full_len -= pad;
1523 		rxm->offset += prot->prepend_size;
1524 		rxm->full_len -= prot->overhead_size;
1525 		tls_advance_record_sn(sk, prot, &tls_ctx->rx);
1526 		ctx->decrypted = 1;
1527 		ctx->saved_data_ready(sk);
1528 	} else {
1529 		*zc = false;
1530 	}
1531 
1532 	return err;
1533 }
1534 
1535 int decrypt_skb(struct sock *sk, struct sk_buff *skb,
1536 		struct scatterlist *sgout)
1537 {
1538 	bool zc = true;
1539 	int chunk;
1540 
1541 	return decrypt_internal(sk, skb, NULL, sgout, &chunk, &zc, false);
1542 }
1543 
1544 static bool tls_sw_advance_skb(struct sock *sk, struct sk_buff *skb,
1545 			       unsigned int len)
1546 {
1547 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1548 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
1549 
1550 	if (skb) {
1551 		struct strp_msg *rxm = strp_msg(skb);
1552 
1553 		if (len < rxm->full_len) {
1554 			rxm->offset += len;
1555 			rxm->full_len -= len;
1556 			return false;
1557 		}
1558 		consume_skb(skb);
1559 	}
1560 
1561 	/* Finished with message */
1562 	ctx->recv_pkt = NULL;
1563 	__strp_unpause(&ctx->strp);
1564 
1565 	return true;
1566 }
1567 
1568 /* This function traverses the rx_list in tls receive context to copies the
1569  * decrypted records into the buffer provided by caller zero copy is not
1570  * true. Further, the records are removed from the rx_list if it is not a peek
1571  * case and the record has been consumed completely.
1572  */
1573 static int process_rx_list(struct tls_sw_context_rx *ctx,
1574 			   struct msghdr *msg,
1575 			   u8 *control,
1576 			   bool *cmsg,
1577 			   size_t skip,
1578 			   size_t len,
1579 			   bool zc,
1580 			   bool is_peek)
1581 {
1582 	struct sk_buff *skb = skb_peek(&ctx->rx_list);
1583 	u8 ctrl = *control;
1584 	u8 msgc = *cmsg;
1585 	struct tls_msg *tlm;
1586 	ssize_t copied = 0;
1587 
1588 	/* Set the record type in 'control' if caller didn't pass it */
1589 	if (!ctrl && skb) {
1590 		tlm = tls_msg(skb);
1591 		ctrl = tlm->control;
1592 	}
1593 
1594 	while (skip && skb) {
1595 		struct strp_msg *rxm = strp_msg(skb);
1596 		tlm = tls_msg(skb);
1597 
1598 		/* Cannot process a record of different type */
1599 		if (ctrl != tlm->control)
1600 			return 0;
1601 
1602 		if (skip < rxm->full_len)
1603 			break;
1604 
1605 		skip = skip - rxm->full_len;
1606 		skb = skb_peek_next(skb, &ctx->rx_list);
1607 	}
1608 
1609 	while (len && skb) {
1610 		struct sk_buff *next_skb;
1611 		struct strp_msg *rxm = strp_msg(skb);
1612 		int chunk = min_t(unsigned int, rxm->full_len - skip, len);
1613 
1614 		tlm = tls_msg(skb);
1615 
1616 		/* Cannot process a record of different type */
1617 		if (ctrl != tlm->control)
1618 			return 0;
1619 
1620 		/* Set record type if not already done. For a non-data record,
1621 		 * do not proceed if record type could not be copied.
1622 		 */
1623 		if (!msgc) {
1624 			int cerr = put_cmsg(msg, SOL_TLS, TLS_GET_RECORD_TYPE,
1625 					    sizeof(ctrl), &ctrl);
1626 			msgc = true;
1627 			if (ctrl != TLS_RECORD_TYPE_DATA) {
1628 				if (cerr || msg->msg_flags & MSG_CTRUNC)
1629 					return -EIO;
1630 
1631 				*cmsg = msgc;
1632 			}
1633 		}
1634 
1635 		if (!zc || (rxm->full_len - skip) > len) {
1636 			int err = skb_copy_datagram_msg(skb, rxm->offset + skip,
1637 						    msg, chunk);
1638 			if (err < 0)
1639 				return err;
1640 		}
1641 
1642 		len = len - chunk;
1643 		copied = copied + chunk;
1644 
1645 		/* Consume the data from record if it is non-peek case*/
1646 		if (!is_peek) {
1647 			rxm->offset = rxm->offset + chunk;
1648 			rxm->full_len = rxm->full_len - chunk;
1649 
1650 			/* Return if there is unconsumed data in the record */
1651 			if (rxm->full_len - skip)
1652 				break;
1653 		}
1654 
1655 		/* The remaining skip-bytes must lie in 1st record in rx_list.
1656 		 * So from the 2nd record, 'skip' should be 0.
1657 		 */
1658 		skip = 0;
1659 
1660 		if (msg)
1661 			msg->msg_flags |= MSG_EOR;
1662 
1663 		next_skb = skb_peek_next(skb, &ctx->rx_list);
1664 
1665 		if (!is_peek) {
1666 			skb_unlink(skb, &ctx->rx_list);
1667 			consume_skb(skb);
1668 		}
1669 
1670 		skb = next_skb;
1671 	}
1672 
1673 	*control = ctrl;
1674 	return copied;
1675 }
1676 
1677 int tls_sw_recvmsg(struct sock *sk,
1678 		   struct msghdr *msg,
1679 		   size_t len,
1680 		   int nonblock,
1681 		   int flags,
1682 		   int *addr_len)
1683 {
1684 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1685 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
1686 	struct tls_prot_info *prot = &tls_ctx->prot_info;
1687 	struct sk_psock *psock;
1688 	unsigned char control = 0;
1689 	ssize_t decrypted = 0;
1690 	struct strp_msg *rxm;
1691 	struct tls_msg *tlm;
1692 	struct sk_buff *skb;
1693 	ssize_t copied = 0;
1694 	bool cmsg = false;
1695 	int target, err = 0;
1696 	long timeo;
1697 	bool is_kvec = iov_iter_is_kvec(&msg->msg_iter);
1698 	bool is_peek = flags & MSG_PEEK;
1699 	int num_async = 0;
1700 
1701 	flags |= nonblock;
1702 
1703 	if (unlikely(flags & MSG_ERRQUEUE))
1704 		return sock_recv_errqueue(sk, msg, len, SOL_IP, IP_RECVERR);
1705 
1706 	psock = sk_psock_get(sk);
1707 	lock_sock(sk);
1708 
1709 	/* Process pending decrypted records. It must be non-zero-copy */
1710 	err = process_rx_list(ctx, msg, &control, &cmsg, 0, len, false,
1711 			      is_peek);
1712 	if (err < 0) {
1713 		tls_err_abort(sk, err);
1714 		goto end;
1715 	} else {
1716 		copied = err;
1717 	}
1718 
1719 	if (len <= copied)
1720 		goto recv_end;
1721 
1722 	target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1723 	len = len - copied;
1724 	timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1725 
1726 	while (len && (decrypted + copied < target || ctx->recv_pkt)) {
1727 		bool retain_skb = false;
1728 		bool zc = false;
1729 		int to_decrypt;
1730 		int chunk = 0;
1731 		bool async_capable;
1732 		bool async = false;
1733 
1734 		skb = tls_wait_data(sk, psock, flags, timeo, &err);
1735 		if (!skb) {
1736 			if (psock) {
1737 				int ret = __tcp_bpf_recvmsg(sk, psock,
1738 							    msg, len, flags);
1739 
1740 				if (ret > 0) {
1741 					decrypted += ret;
1742 					len -= ret;
1743 					continue;
1744 				}
1745 			}
1746 			goto recv_end;
1747 		} else {
1748 			tlm = tls_msg(skb);
1749 			if (prot->version == TLS_1_3_VERSION)
1750 				tlm->control = 0;
1751 			else
1752 				tlm->control = ctx->control;
1753 		}
1754 
1755 		rxm = strp_msg(skb);
1756 
1757 		to_decrypt = rxm->full_len - prot->overhead_size;
1758 
1759 		if (to_decrypt <= len && !is_kvec && !is_peek &&
1760 		    ctx->control == TLS_RECORD_TYPE_DATA &&
1761 		    prot->version != TLS_1_3_VERSION)
1762 			zc = true;
1763 
1764 		/* Do not use async mode if record is non-data */
1765 		if (ctx->control == TLS_RECORD_TYPE_DATA)
1766 			async_capable = ctx->async_capable;
1767 		else
1768 			async_capable = false;
1769 
1770 		err = decrypt_skb_update(sk, skb, &msg->msg_iter,
1771 					 &chunk, &zc, async_capable);
1772 		if (err < 0 && err != -EINPROGRESS) {
1773 			tls_err_abort(sk, EBADMSG);
1774 			goto recv_end;
1775 		}
1776 
1777 		if (err == -EINPROGRESS) {
1778 			async = true;
1779 			num_async++;
1780 		} else if (prot->version == TLS_1_3_VERSION) {
1781 			tlm->control = ctx->control;
1782 		}
1783 
1784 		/* If the type of records being processed is not known yet,
1785 		 * set it to record type just dequeued. If it is already known,
1786 		 * but does not match the record type just dequeued, go to end.
1787 		 * We always get record type here since for tls1.2, record type
1788 		 * is known just after record is dequeued from stream parser.
1789 		 * For tls1.3, we disable async.
1790 		 */
1791 
1792 		if (!control)
1793 			control = tlm->control;
1794 		else if (control != tlm->control)
1795 			goto recv_end;
1796 
1797 		if (!cmsg) {
1798 			int cerr;
1799 
1800 			cerr = put_cmsg(msg, SOL_TLS, TLS_GET_RECORD_TYPE,
1801 					sizeof(control), &control);
1802 			cmsg = true;
1803 			if (control != TLS_RECORD_TYPE_DATA) {
1804 				if (cerr || msg->msg_flags & MSG_CTRUNC) {
1805 					err = -EIO;
1806 					goto recv_end;
1807 				}
1808 			}
1809 		}
1810 
1811 		if (async)
1812 			goto pick_next_record;
1813 
1814 		if (!zc) {
1815 			if (rxm->full_len > len) {
1816 				retain_skb = true;
1817 				chunk = len;
1818 			} else {
1819 				chunk = rxm->full_len;
1820 			}
1821 
1822 			err = skb_copy_datagram_msg(skb, rxm->offset,
1823 						    msg, chunk);
1824 			if (err < 0)
1825 				goto recv_end;
1826 
1827 			if (!is_peek) {
1828 				rxm->offset = rxm->offset + chunk;
1829 				rxm->full_len = rxm->full_len - chunk;
1830 			}
1831 		}
1832 
1833 pick_next_record:
1834 		if (chunk > len)
1835 			chunk = len;
1836 
1837 		decrypted += chunk;
1838 		len -= chunk;
1839 
1840 		/* For async or peek case, queue the current skb */
1841 		if (async || is_peek || retain_skb) {
1842 			skb_queue_tail(&ctx->rx_list, skb);
1843 			skb = NULL;
1844 		}
1845 
1846 		if (tls_sw_advance_skb(sk, skb, chunk)) {
1847 			/* Return full control message to
1848 			 * userspace before trying to parse
1849 			 * another message type
1850 			 */
1851 			msg->msg_flags |= MSG_EOR;
1852 			if (ctx->control != TLS_RECORD_TYPE_DATA)
1853 				goto recv_end;
1854 		} else {
1855 			break;
1856 		}
1857 	}
1858 
1859 recv_end:
1860 	if (num_async) {
1861 		/* Wait for all previously submitted records to be decrypted */
1862 		smp_store_mb(ctx->async_notify, true);
1863 		if (atomic_read(&ctx->decrypt_pending)) {
1864 			err = crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
1865 			if (err) {
1866 				/* one of async decrypt failed */
1867 				tls_err_abort(sk, err);
1868 				copied = 0;
1869 				decrypted = 0;
1870 				goto end;
1871 			}
1872 		} else {
1873 			reinit_completion(&ctx->async_wait.completion);
1874 		}
1875 		WRITE_ONCE(ctx->async_notify, false);
1876 
1877 		/* Drain records from the rx_list & copy if required */
1878 		if (is_peek || is_kvec)
1879 			err = process_rx_list(ctx, msg, &control, &cmsg, copied,
1880 					      decrypted, false, is_peek);
1881 		else
1882 			err = process_rx_list(ctx, msg, &control, &cmsg, 0,
1883 					      decrypted, true, is_peek);
1884 		if (err < 0) {
1885 			tls_err_abort(sk, err);
1886 			copied = 0;
1887 			goto end;
1888 		}
1889 	}
1890 
1891 	copied += decrypted;
1892 
1893 end:
1894 	release_sock(sk);
1895 	if (psock)
1896 		sk_psock_put(sk, psock);
1897 	return copied ? : err;
1898 }
1899 
1900 ssize_t tls_sw_splice_read(struct socket *sock,  loff_t *ppos,
1901 			   struct pipe_inode_info *pipe,
1902 			   size_t len, unsigned int flags)
1903 {
1904 	struct tls_context *tls_ctx = tls_get_ctx(sock->sk);
1905 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
1906 	struct strp_msg *rxm = NULL;
1907 	struct sock *sk = sock->sk;
1908 	struct sk_buff *skb;
1909 	ssize_t copied = 0;
1910 	int err = 0;
1911 	long timeo;
1912 	int chunk;
1913 	bool zc = false;
1914 
1915 	lock_sock(sk);
1916 
1917 	timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1918 
1919 	skb = tls_wait_data(sk, NULL, flags, timeo, &err);
1920 	if (!skb)
1921 		goto splice_read_end;
1922 
1923 	if (!ctx->decrypted) {
1924 		err = decrypt_skb_update(sk, skb, NULL, &chunk, &zc, false);
1925 
1926 		/* splice does not support reading control messages */
1927 		if (ctx->control != TLS_RECORD_TYPE_DATA) {
1928 			err = -ENOTSUPP;
1929 			goto splice_read_end;
1930 		}
1931 
1932 		if (err < 0) {
1933 			tls_err_abort(sk, EBADMSG);
1934 			goto splice_read_end;
1935 		}
1936 		ctx->decrypted = 1;
1937 	}
1938 	rxm = strp_msg(skb);
1939 
1940 	chunk = min_t(unsigned int, rxm->full_len, len);
1941 	copied = skb_splice_bits(skb, sk, rxm->offset, pipe, chunk, flags);
1942 	if (copied < 0)
1943 		goto splice_read_end;
1944 
1945 	if (likely(!(flags & MSG_PEEK)))
1946 		tls_sw_advance_skb(sk, skb, copied);
1947 
1948 splice_read_end:
1949 	release_sock(sk);
1950 	return copied ? : err;
1951 }
1952 
1953 bool tls_sw_stream_read(const struct sock *sk)
1954 {
1955 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1956 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
1957 	bool ingress_empty = true;
1958 	struct sk_psock *psock;
1959 
1960 	rcu_read_lock();
1961 	psock = sk_psock(sk);
1962 	if (psock)
1963 		ingress_empty = list_empty(&psock->ingress_msg);
1964 	rcu_read_unlock();
1965 
1966 	return !ingress_empty || ctx->recv_pkt ||
1967 		!skb_queue_empty(&ctx->rx_list);
1968 }
1969 
1970 static int tls_read_size(struct strparser *strp, struct sk_buff *skb)
1971 {
1972 	struct tls_context *tls_ctx = tls_get_ctx(strp->sk);
1973 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
1974 	struct tls_prot_info *prot = &tls_ctx->prot_info;
1975 	char header[TLS_HEADER_SIZE + MAX_IV_SIZE];
1976 	struct strp_msg *rxm = strp_msg(skb);
1977 	size_t cipher_overhead;
1978 	size_t data_len = 0;
1979 	int ret;
1980 
1981 	/* Verify that we have a full TLS header, or wait for more data */
1982 	if (rxm->offset + prot->prepend_size > skb->len)
1983 		return 0;
1984 
1985 	/* Sanity-check size of on-stack buffer. */
1986 	if (WARN_ON(prot->prepend_size > sizeof(header))) {
1987 		ret = -EINVAL;
1988 		goto read_failure;
1989 	}
1990 
1991 	/* Linearize header to local buffer */
1992 	ret = skb_copy_bits(skb, rxm->offset, header, prot->prepend_size);
1993 
1994 	if (ret < 0)
1995 		goto read_failure;
1996 
1997 	ctx->control = header[0];
1998 
1999 	data_len = ((header[4] & 0xFF) | (header[3] << 8));
2000 
2001 	cipher_overhead = prot->tag_size;
2002 	if (prot->version != TLS_1_3_VERSION)
2003 		cipher_overhead += prot->iv_size;
2004 
2005 	if (data_len > TLS_MAX_PAYLOAD_SIZE + cipher_overhead +
2006 	    prot->tail_size) {
2007 		ret = -EMSGSIZE;
2008 		goto read_failure;
2009 	}
2010 	if (data_len < cipher_overhead) {
2011 		ret = -EBADMSG;
2012 		goto read_failure;
2013 	}
2014 
2015 	/* Note that both TLS1.3 and TLS1.2 use TLS_1_2 version here */
2016 	if (header[1] != TLS_1_2_VERSION_MINOR ||
2017 	    header[2] != TLS_1_2_VERSION_MAJOR) {
2018 		ret = -EINVAL;
2019 		goto read_failure;
2020 	}
2021 
2022 	tls_device_rx_resync_new_rec(strp->sk, data_len + TLS_HEADER_SIZE,
2023 				     TCP_SKB_CB(skb)->seq + rxm->offset);
2024 	return data_len + TLS_HEADER_SIZE;
2025 
2026 read_failure:
2027 	tls_err_abort(strp->sk, ret);
2028 
2029 	return ret;
2030 }
2031 
2032 static void tls_queue(struct strparser *strp, struct sk_buff *skb)
2033 {
2034 	struct tls_context *tls_ctx = tls_get_ctx(strp->sk);
2035 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
2036 
2037 	ctx->decrypted = 0;
2038 
2039 	ctx->recv_pkt = skb;
2040 	strp_pause(strp);
2041 
2042 	ctx->saved_data_ready(strp->sk);
2043 }
2044 
2045 static void tls_data_ready(struct sock *sk)
2046 {
2047 	struct tls_context *tls_ctx = tls_get_ctx(sk);
2048 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
2049 	struct sk_psock *psock;
2050 
2051 	strp_data_ready(&ctx->strp);
2052 
2053 	psock = sk_psock_get(sk);
2054 	if (psock && !list_empty(&psock->ingress_msg)) {
2055 		ctx->saved_data_ready(sk);
2056 		sk_psock_put(sk, psock);
2057 	}
2058 }
2059 
2060 void tls_sw_cancel_work_tx(struct tls_context *tls_ctx)
2061 {
2062 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
2063 
2064 	set_bit(BIT_TX_CLOSING, &ctx->tx_bitmask);
2065 	set_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask);
2066 	cancel_delayed_work_sync(&ctx->tx_work.work);
2067 }
2068 
2069 void tls_sw_release_resources_tx(struct sock *sk)
2070 {
2071 	struct tls_context *tls_ctx = tls_get_ctx(sk);
2072 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
2073 	struct tls_rec *rec, *tmp;
2074 
2075 	/* Wait for any pending async encryptions to complete */
2076 	smp_store_mb(ctx->async_notify, true);
2077 	if (atomic_read(&ctx->encrypt_pending))
2078 		crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
2079 
2080 	tls_tx_records(sk, -1);
2081 
2082 	/* Free up un-sent records in tx_list. First, free
2083 	 * the partially sent record if any at head of tx_list.
2084 	 */
2085 	if (tls_free_partial_record(sk, tls_ctx)) {
2086 		rec = list_first_entry(&ctx->tx_list,
2087 				       struct tls_rec, list);
2088 		list_del(&rec->list);
2089 		sk_msg_free(sk, &rec->msg_plaintext);
2090 		kfree(rec);
2091 	}
2092 
2093 	list_for_each_entry_safe(rec, tmp, &ctx->tx_list, list) {
2094 		list_del(&rec->list);
2095 		sk_msg_free(sk, &rec->msg_encrypted);
2096 		sk_msg_free(sk, &rec->msg_plaintext);
2097 		kfree(rec);
2098 	}
2099 
2100 	crypto_free_aead(ctx->aead_send);
2101 	tls_free_open_rec(sk);
2102 }
2103 
2104 void tls_sw_free_ctx_tx(struct tls_context *tls_ctx)
2105 {
2106 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
2107 
2108 	kfree(ctx);
2109 }
2110 
2111 void tls_sw_release_resources_rx(struct sock *sk)
2112 {
2113 	struct tls_context *tls_ctx = tls_get_ctx(sk);
2114 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
2115 
2116 	kfree(tls_ctx->rx.rec_seq);
2117 	kfree(tls_ctx->rx.iv);
2118 
2119 	if (ctx->aead_recv) {
2120 		kfree_skb(ctx->recv_pkt);
2121 		ctx->recv_pkt = NULL;
2122 		skb_queue_purge(&ctx->rx_list);
2123 		crypto_free_aead(ctx->aead_recv);
2124 		strp_stop(&ctx->strp);
2125 		/* If tls_sw_strparser_arm() was not called (cleanup paths)
2126 		 * we still want to strp_stop(), but sk->sk_data_ready was
2127 		 * never swapped.
2128 		 */
2129 		if (ctx->saved_data_ready) {
2130 			write_lock_bh(&sk->sk_callback_lock);
2131 			sk->sk_data_ready = ctx->saved_data_ready;
2132 			write_unlock_bh(&sk->sk_callback_lock);
2133 		}
2134 	}
2135 }
2136 
2137 void tls_sw_strparser_done(struct tls_context *tls_ctx)
2138 {
2139 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
2140 
2141 	strp_done(&ctx->strp);
2142 }
2143 
2144 void tls_sw_free_ctx_rx(struct tls_context *tls_ctx)
2145 {
2146 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
2147 
2148 	kfree(ctx);
2149 }
2150 
2151 void tls_sw_free_resources_rx(struct sock *sk)
2152 {
2153 	struct tls_context *tls_ctx = tls_get_ctx(sk);
2154 
2155 	tls_sw_release_resources_rx(sk);
2156 	tls_sw_free_ctx_rx(tls_ctx);
2157 }
2158 
2159 /* The work handler to transmitt the encrypted records in tx_list */
2160 static void tx_work_handler(struct work_struct *work)
2161 {
2162 	struct delayed_work *delayed_work = to_delayed_work(work);
2163 	struct tx_work *tx_work = container_of(delayed_work,
2164 					       struct tx_work, work);
2165 	struct sock *sk = tx_work->sk;
2166 	struct tls_context *tls_ctx = tls_get_ctx(sk);
2167 	struct tls_sw_context_tx *ctx;
2168 
2169 	if (unlikely(!tls_ctx))
2170 		return;
2171 
2172 	ctx = tls_sw_ctx_tx(tls_ctx);
2173 	if (test_bit(BIT_TX_CLOSING, &ctx->tx_bitmask))
2174 		return;
2175 
2176 	if (!test_and_clear_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask))
2177 		return;
2178 	lock_sock(sk);
2179 	tls_tx_records(sk, -1);
2180 	release_sock(sk);
2181 }
2182 
2183 void tls_sw_write_space(struct sock *sk, struct tls_context *ctx)
2184 {
2185 	struct tls_sw_context_tx *tx_ctx = tls_sw_ctx_tx(ctx);
2186 
2187 	/* Schedule the transmission if tx list is ready */
2188 	if (is_tx_ready(tx_ctx) && !sk->sk_write_pending) {
2189 		/* Schedule the transmission */
2190 		if (!test_and_set_bit(BIT_TX_SCHEDULED,
2191 				      &tx_ctx->tx_bitmask))
2192 			schedule_delayed_work(&tx_ctx->tx_work.work, 0);
2193 	}
2194 }
2195 
2196 void tls_sw_strparser_arm(struct sock *sk, struct tls_context *tls_ctx)
2197 {
2198 	struct tls_sw_context_rx *rx_ctx = tls_sw_ctx_rx(tls_ctx);
2199 
2200 	write_lock_bh(&sk->sk_callback_lock);
2201 	rx_ctx->saved_data_ready = sk->sk_data_ready;
2202 	sk->sk_data_ready = tls_data_ready;
2203 	write_unlock_bh(&sk->sk_callback_lock);
2204 
2205 	strp_check_rcv(&rx_ctx->strp);
2206 }
2207 
2208 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx)
2209 {
2210 	struct tls_context *tls_ctx = tls_get_ctx(sk);
2211 	struct tls_prot_info *prot = &tls_ctx->prot_info;
2212 	struct tls_crypto_info *crypto_info;
2213 	struct tls12_crypto_info_aes_gcm_128 *gcm_128_info;
2214 	struct tls12_crypto_info_aes_gcm_256 *gcm_256_info;
2215 	struct tls12_crypto_info_aes_ccm_128 *ccm_128_info;
2216 	struct tls_sw_context_tx *sw_ctx_tx = NULL;
2217 	struct tls_sw_context_rx *sw_ctx_rx = NULL;
2218 	struct cipher_context *cctx;
2219 	struct crypto_aead **aead;
2220 	struct strp_callbacks cb;
2221 	u16 nonce_size, tag_size, iv_size, rec_seq_size, salt_size;
2222 	struct crypto_tfm *tfm;
2223 	char *iv, *rec_seq, *key, *salt, *cipher_name;
2224 	size_t keysize;
2225 	int rc = 0;
2226 
2227 	if (!ctx) {
2228 		rc = -EINVAL;
2229 		goto out;
2230 	}
2231 
2232 	if (tx) {
2233 		if (!ctx->priv_ctx_tx) {
2234 			sw_ctx_tx = kzalloc(sizeof(*sw_ctx_tx), GFP_KERNEL);
2235 			if (!sw_ctx_tx) {
2236 				rc = -ENOMEM;
2237 				goto out;
2238 			}
2239 			ctx->priv_ctx_tx = sw_ctx_tx;
2240 		} else {
2241 			sw_ctx_tx =
2242 				(struct tls_sw_context_tx *)ctx->priv_ctx_tx;
2243 		}
2244 	} else {
2245 		if (!ctx->priv_ctx_rx) {
2246 			sw_ctx_rx = kzalloc(sizeof(*sw_ctx_rx), GFP_KERNEL);
2247 			if (!sw_ctx_rx) {
2248 				rc = -ENOMEM;
2249 				goto out;
2250 			}
2251 			ctx->priv_ctx_rx = sw_ctx_rx;
2252 		} else {
2253 			sw_ctx_rx =
2254 				(struct tls_sw_context_rx *)ctx->priv_ctx_rx;
2255 		}
2256 	}
2257 
2258 	if (tx) {
2259 		crypto_init_wait(&sw_ctx_tx->async_wait);
2260 		crypto_info = &ctx->crypto_send.info;
2261 		cctx = &ctx->tx;
2262 		aead = &sw_ctx_tx->aead_send;
2263 		INIT_LIST_HEAD(&sw_ctx_tx->tx_list);
2264 		INIT_DELAYED_WORK(&sw_ctx_tx->tx_work.work, tx_work_handler);
2265 		sw_ctx_tx->tx_work.sk = sk;
2266 	} else {
2267 		crypto_init_wait(&sw_ctx_rx->async_wait);
2268 		crypto_info = &ctx->crypto_recv.info;
2269 		cctx = &ctx->rx;
2270 		skb_queue_head_init(&sw_ctx_rx->rx_list);
2271 		aead = &sw_ctx_rx->aead_recv;
2272 	}
2273 
2274 	switch (crypto_info->cipher_type) {
2275 	case TLS_CIPHER_AES_GCM_128: {
2276 		nonce_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
2277 		tag_size = TLS_CIPHER_AES_GCM_128_TAG_SIZE;
2278 		iv_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
2279 		iv = ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->iv;
2280 		rec_seq_size = TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE;
2281 		rec_seq =
2282 		 ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->rec_seq;
2283 		gcm_128_info =
2284 			(struct tls12_crypto_info_aes_gcm_128 *)crypto_info;
2285 		keysize = TLS_CIPHER_AES_GCM_128_KEY_SIZE;
2286 		key = gcm_128_info->key;
2287 		salt = gcm_128_info->salt;
2288 		salt_size = TLS_CIPHER_AES_GCM_128_SALT_SIZE;
2289 		cipher_name = "gcm(aes)";
2290 		break;
2291 	}
2292 	case TLS_CIPHER_AES_GCM_256: {
2293 		nonce_size = TLS_CIPHER_AES_GCM_256_IV_SIZE;
2294 		tag_size = TLS_CIPHER_AES_GCM_256_TAG_SIZE;
2295 		iv_size = TLS_CIPHER_AES_GCM_256_IV_SIZE;
2296 		iv = ((struct tls12_crypto_info_aes_gcm_256 *)crypto_info)->iv;
2297 		rec_seq_size = TLS_CIPHER_AES_GCM_256_REC_SEQ_SIZE;
2298 		rec_seq =
2299 		 ((struct tls12_crypto_info_aes_gcm_256 *)crypto_info)->rec_seq;
2300 		gcm_256_info =
2301 			(struct tls12_crypto_info_aes_gcm_256 *)crypto_info;
2302 		keysize = TLS_CIPHER_AES_GCM_256_KEY_SIZE;
2303 		key = gcm_256_info->key;
2304 		salt = gcm_256_info->salt;
2305 		salt_size = TLS_CIPHER_AES_GCM_256_SALT_SIZE;
2306 		cipher_name = "gcm(aes)";
2307 		break;
2308 	}
2309 	case TLS_CIPHER_AES_CCM_128: {
2310 		nonce_size = TLS_CIPHER_AES_CCM_128_IV_SIZE;
2311 		tag_size = TLS_CIPHER_AES_CCM_128_TAG_SIZE;
2312 		iv_size = TLS_CIPHER_AES_CCM_128_IV_SIZE;
2313 		iv = ((struct tls12_crypto_info_aes_ccm_128 *)crypto_info)->iv;
2314 		rec_seq_size = TLS_CIPHER_AES_CCM_128_REC_SEQ_SIZE;
2315 		rec_seq =
2316 		((struct tls12_crypto_info_aes_ccm_128 *)crypto_info)->rec_seq;
2317 		ccm_128_info =
2318 		(struct tls12_crypto_info_aes_ccm_128 *)crypto_info;
2319 		keysize = TLS_CIPHER_AES_CCM_128_KEY_SIZE;
2320 		key = ccm_128_info->key;
2321 		salt = ccm_128_info->salt;
2322 		salt_size = TLS_CIPHER_AES_CCM_128_SALT_SIZE;
2323 		cipher_name = "ccm(aes)";
2324 		break;
2325 	}
2326 	default:
2327 		rc = -EINVAL;
2328 		goto free_priv;
2329 	}
2330 
2331 	/* Sanity-check the sizes for stack allocations. */
2332 	if (iv_size > MAX_IV_SIZE || nonce_size > MAX_IV_SIZE ||
2333 	    rec_seq_size > TLS_MAX_REC_SEQ_SIZE) {
2334 		rc = -EINVAL;
2335 		goto free_priv;
2336 	}
2337 
2338 	if (crypto_info->version == TLS_1_3_VERSION) {
2339 		nonce_size = 0;
2340 		prot->aad_size = TLS_HEADER_SIZE;
2341 		prot->tail_size = 1;
2342 	} else {
2343 		prot->aad_size = TLS_AAD_SPACE_SIZE;
2344 		prot->tail_size = 0;
2345 	}
2346 
2347 	prot->version = crypto_info->version;
2348 	prot->cipher_type = crypto_info->cipher_type;
2349 	prot->prepend_size = TLS_HEADER_SIZE + nonce_size;
2350 	prot->tag_size = tag_size;
2351 	prot->overhead_size = prot->prepend_size +
2352 			      prot->tag_size + prot->tail_size;
2353 	prot->iv_size = iv_size;
2354 	prot->salt_size = salt_size;
2355 	cctx->iv = kmalloc(iv_size + salt_size, GFP_KERNEL);
2356 	if (!cctx->iv) {
2357 		rc = -ENOMEM;
2358 		goto free_priv;
2359 	}
2360 	/* Note: 128 & 256 bit salt are the same size */
2361 	prot->rec_seq_size = rec_seq_size;
2362 	memcpy(cctx->iv, salt, salt_size);
2363 	memcpy(cctx->iv + salt_size, iv, iv_size);
2364 	cctx->rec_seq = kmemdup(rec_seq, rec_seq_size, GFP_KERNEL);
2365 	if (!cctx->rec_seq) {
2366 		rc = -ENOMEM;
2367 		goto free_iv;
2368 	}
2369 
2370 	if (!*aead) {
2371 		*aead = crypto_alloc_aead(cipher_name, 0, 0);
2372 		if (IS_ERR(*aead)) {
2373 			rc = PTR_ERR(*aead);
2374 			*aead = NULL;
2375 			goto free_rec_seq;
2376 		}
2377 	}
2378 
2379 	ctx->push_pending_record = tls_sw_push_pending_record;
2380 
2381 	rc = crypto_aead_setkey(*aead, key, keysize);
2382 
2383 	if (rc)
2384 		goto free_aead;
2385 
2386 	rc = crypto_aead_setauthsize(*aead, prot->tag_size);
2387 	if (rc)
2388 		goto free_aead;
2389 
2390 	if (sw_ctx_rx) {
2391 		tfm = crypto_aead_tfm(sw_ctx_rx->aead_recv);
2392 
2393 		if (crypto_info->version == TLS_1_3_VERSION)
2394 			sw_ctx_rx->async_capable = 0;
2395 		else
2396 			sw_ctx_rx->async_capable =
2397 				!!(tfm->__crt_alg->cra_flags &
2398 				   CRYPTO_ALG_ASYNC);
2399 
2400 		/* Set up strparser */
2401 		memset(&cb, 0, sizeof(cb));
2402 		cb.rcv_msg = tls_queue;
2403 		cb.parse_msg = tls_read_size;
2404 
2405 		strp_init(&sw_ctx_rx->strp, sk, &cb);
2406 	}
2407 
2408 	goto out;
2409 
2410 free_aead:
2411 	crypto_free_aead(*aead);
2412 	*aead = NULL;
2413 free_rec_seq:
2414 	kfree(cctx->rec_seq);
2415 	cctx->rec_seq = NULL;
2416 free_iv:
2417 	kfree(cctx->iv);
2418 	cctx->iv = NULL;
2419 free_priv:
2420 	if (tx) {
2421 		kfree(ctx->priv_ctx_tx);
2422 		ctx->priv_ctx_tx = NULL;
2423 	} else {
2424 		kfree(ctx->priv_ctx_rx);
2425 		ctx->priv_ctx_rx = NULL;
2426 	}
2427 out:
2428 	return rc;
2429 }
2430